Joint structure for laminates



April 24,. 1951 4 c; G. BENNETT 2,550,520

JOINT STRUCTURE RoR LAMINATES Filed Nov. 12, 194? IN V EN TOR. 7a/ence 6. Berme ATM/RNE? Patented Apr. 24, Y1951 Y s, ,QlafeeeeiG-Beeneieleaiilvfaiee Calif,-

1 1 ApplictionNovmber 1e47,s`ria1fN solaires. (Ciliegio-:4er i it very diflicult to seal either to itselfbrrtoY anunlike layer.

ForA example .vegetable Vparchment paper .isa verydesirable material for certainuses but it Vhas the property of vpermitting the passageofmoisture or Wateryvaponand due `toathis characteristic and others is ditcult to VA. joinpermanently.v In order tojutilize the desirable characteristics, ofthe vegetable parchment While at thegsametime avoiding moisture loss, in cases'where'it, is a `olisac'lvantagaa laminate having, for example, a layer o f water-proof -cellophane ,may be utilized. v',When,l however, it l is, attempted to makea joint, ras inthe pril-271eara r tion of a bag, it will befound thatthe commonly used lap joint requiresasecurementof parchment to cellophane. A.' Ifhishas proved 11.0 be avery difficult problem to solve.

- The invention disclosed herein provides a solution to the above-mentioned.problemin that it Y allovvsa strong, impervious` joint to be made,

,avoiding the, necessity for securing of unlike .materialstogether@ :,It is an object ,ofthe present invention to `provide a joint structurefor use in' connection With laminates of unlike layers, wherebya strong .and satisfactory joint may `loe achieved..l

VA further object is to provide laminated blanks for bags, tubes, etc., said blanks having an edge .construction adapted to` heralded over` and sey cured to yanother edgeptmgivea mecharufcally sound joint. y n

vA still further object isto'provide bags, tubes,

1etc'.;' constructed of aflaminatejd sheet material having unlike layers, and including a joint Y in which an outer layer is securely adhered to itself ,ratherthan to an unlikematerial.-

' In the drawing which accompaniesthe application, n

Figure l is a cross-section ,of a particular lami- Y nate illustrating the inventions f ,l

Figure 2 isa Asimilar section showing a joint 35, intheform ofthe ioiniorrseamehowh in gjmade by. themes ,ofather material ,indicated Ain `.Figline p j Figure 3; representationofa differenttype of jointastiuuitilizing,the same.stiaicture,y 1

In the drawingsnumerahl refers to a, layer whichmay he,- for .examplaparehment paper.

. Numeralgll refers to anunlike material, foreig- ,f ample., cellophane, whilethetwo sheet materials f are secured ,together `byfga layer, I2, forexample,

10;.of petroleum wax., f

, AsindieatedLthe cellenbaile isiooatedfonrone or vboth ,sides in this .instahee,-on hoih Sides,.ihe coating i3 heine heat-.Sealing lacquer, ,Whileihe @canned may beheatfsealmg lacqueior a mois.-

15 ture-proofing. For reasons which will become apparent, the eel,loiohanen `laver y; extends` bevond .the'sbouhdarx edge of thepaper; layer.'` :Consideration o f v`th,e naiu1ee of, the laminate, Will indicate that if ar sheet ,of this material having coinci- 20 .dentedgesbe turned uaround; upon` itself to secure Vcellophane e will ,A inevitably have to yloel secured to the Perehmenileaper--- ,r .Iihaslpreved iohe dificultgtovmake such ajoint satisfactory in any re 25.,.*speet and .impossible ,to Seeiireaareallr ,ealisfaevery Joint. between. maierials.V oi, si.1eh` difierehi reharaeierieiiee On. ooheiderationoi Figure whiehjehouaa lap joint in accordance wimmy invention, it

3oY will ,be notedthai-iheeellophahe layer; l," will' be `secured to itself in theaarea indicated by the ,numeral ,l 51 .If them forfexarhple, layers i3 arid 14 are ,beih. oi a heai-eealihe laeeuer, `a `Salesiantial ahdrermaheriiioiniie,eaeili aeeiliefi,` l

.urea however. theedse oithe ,Sheet ma shown at the top ,is secured not only at thearea V[5,3 but further overlaps lthe',parchnrient paper layer| 0., In theqaseof the particular materials signed to be secured'by the applicationloiheat and Pressure. vthus, not. only will eellehhahefbe sealed to cellophane in the area markedwl, but r the `Wax 'from layer l2 will exude from the edges soithenflaterial at I6fand; |1 to form secondary ,-aeals.;` l In ome oftheruses toWhichalaminate Asuch asis described above is put, the vegetable parchzmenepaper .layer is-on iheinside of ,the has er :so liner andiS- Suhieei toihe ,ihuehee ,off-moisture vIn therconventional lap joint,r even if Athe cellophane werevreasonably vWell securedto the parche ment `paper-in 1Bhe beginning, `the moisture moving by capillary aeiion-ihtotheeeeured portoneof u.I the parchment will cause the joint v11o fail. 5.,;

n the joint structure shown in Figure 2, moisture in the parchment paper layers is stopped, first by the wax exudate Il from penetrating to the joint area l5. Moisture within the wrapper or bag, considered as the upper layer in this instance, is barred by the exudate I6.

In Figure 3, I have shown a joint structure wherein a portion of the parchment paper layer Il] is removedfrom 4adjacent the terminal edge area of the sheet :I l; rl'he other edge of thefs'heet butts substantially against the edge ofthe parchment sheet I0. It may be referred to as a buttjoint, though, of course, it is not strictly such. Here again, the area of the overlapfgcnstitutes a strong and impervious joint andthe wax exudate I8 seals the edges of the twosheetstovim prove the imperviousness of ..theijoint..

One of the substantial uses for the joint structure which I have described is in thecasingtof certain meat and 'lsh sausages, also cheeses, tamales,f"etc. Y- f-This' -iequiies a `tube which is! best constructed from a long paper strip. ini-"this embodiment of theV inventioml the* strip -will' be as longasfis convenient' and, forexamplegtwelve inches wide, referring tolfthecellophane, while theparchment paper-Slayers secured theretol'have 'coincident edges 'onloneside and will be',-for'5ex ample, only eleveninches widejvwherebyithe cellophane vlayerfe'xtends' approximately an inch beyond one edge of the parchment-paperflayer. *Such'a'structurefihasbeen found well-'suited to fthe' preparationf-ofV a 'strongandI secure' tube for y"the -casing vf-l"certain'typesv of sausages and the 1f A further embodimentrlofthe invention is involved in, the preparation of blanks 4-to be 'made f into 'bags Lorsacks Inthis instance, the flongitudinalfseam` or jointof thefbagmay lbe pron vided for -by-havi-ng-'one edge of the laminated structure asindicatedfinF-igure Vl. For example, to prepare` a bag? fapprox'iniately5 8*' by 6 inches, "one may prepare a-`rectangularblank approximately 9 by --iiichesf and "oneLl ofifthe*l 9 "iiich 'Y' edgesgwillhave`-`one`fof f=the layers fof--theglamin'ate i extendedbeyond the-other v`orv'thers'f, asiindicated While I have'fini'theiabove'dreferredlto particulai' materials Vfor the-various layers andv adhesives, it= 4will flbe obvious that a* great deal vof Lvariation "is possible. The-fventi'on 'willi nd util-ityin any case where a" laminated-@sheetmaterialmust 'be "joined 4by ledges llike-'thoseeonsidered abvevfand f'wli'ere; themateria1s are?l ofs'iichfinature that to -s`eeureone tothe other impracticabl oneven '"impossible. VThe 'i' term paper fincludesipaper especially treated, as with melamine resins; etc.

@Some ofthe Variations? poss'iblewillbe alluded AJtoin the following'and-others will'becor'ne-*apparent to-those considering"v thev application of the invention. Y

1H VIn the drawi-Iigsthelayer '-'I Il fmfay be `a' paper; zlcellophane;` either coated or uncoatedfandieither Vlacquered or unlacquered; Y cellulose acetate, coated or 'unco'atedgf thylfcelllose;polyvinyl -'cl`1loride,`vr plyvinylidine, i ipolfyamide, l`l=ethylene resin, polystyrene'g-' wax paper`, -lnetal-4 foil, cloth, -or in fact-'almostany sheet* materialide'sired.

l 4The layer I l Vinay-beanyofthenflaterialsnamed above for vlayer I-ll;orVotliers;v :'ai-idf-the'v invention @Will be- Of utility2 as -longias'' the'f layerSi-:arefof Sub- Lstantia'lly dierent characteristics.

4 silicate of soda, starch, dextrin, glue or animal or Vegetable origin, latex, resin dispersions, casein, wax, asphalt, resin, Vegetable wax, ester gum, cellulose nitrate, styrene, Wax-alkyd-resin 5V compound, cornstarch, bitumin, silicone compositions or any of many other like materials.

The coatings I3 and i4 may be any of the coatings used in the arts; in connection with any of vthematerials mentioned for layer ll, for exlO .-'ample, lacquer @such asl?, cellulose i'iitrate, ethyl cellulose, cyclized rubber, vinylidene chloride, .cellulose acetate, aqueous or non-aqueous, organic ior inorganic adhesives or the known pressure i?sensitiveicadhesiiies may be used.

..15 in casenone. or the coatings involved in any "bf `th`e"la1n;irrat`ed layers is of a suitably adhesive ama-ture;*anfauhesiyespecially compatible with the layer which contains the extended marginal portioirwill be employed. In this case, again, the

2O problem of securing unlike layers to each other fis 'ayoidedby the ilse 0I1-thezjointstructure which I'jliavedevised.

'-It" isi to''bepointedioutfthatthe layer 'which has #the"extendingf'margin:ne'ednot beV an' outeri'layer as has been described above, but may be selected only on the-ig'round?v that `it i oiersithe '.b'est pos- Ysibllities o- Asecuring thefe'dgesfiof the` structure -togetlierj-fMore thanffthree layersfrnay be tineluded-'Jinthe='lamina`te.

i I; u'seithe 'termif.feffectivelyfparallel zztoi. cover instances i1 where "f-the'? edges1 mightV `be i pinked -or `'.scaliopedV for? decorative forati other ':.reasons,f for others in`-l1 which: they-flare .not':.V mathematically claim: #li-"A, 'jointL14 structure' ff'ashioned -from acompositefsheetfhaving ai rst sheet: memberv having ai-la'yer oflheat-sealingiimaterial on each 1 side 40 heat!sealingila'yersA terminating' shortiof-the Ysheet edgeto piovidefanwexposed terminal .area of. the

heat sealing mate'riaL -and a :secondi ysheet mem- -fber' overlying and *oo-extensive with .the y. paran layeri 1the'jo`int comprising .said'rcomposite i5 `Sheetffj oined to 'litself @with a portion n Ythereof extending-- o'v'er andco'vering the exposedfterminal-areafand'witl'heat sealing surfaoesion, the "-lrst Y :sheetlin 'ffaeeeto'efaoe' engagement, the.V .petr'oleum lwax' layer havingbeen melted toprovide aseal-betweenthe adjacent-(abutting terminal edges of the sheet.

" -2.- A-ljoint^ structureffashioned i from a' com- Lposite sheetehaving ar'stf'sheet member having a--lla-yer' of@ h'eat sealinglmaterial f on eachkside heat sealing layers terminatingfshortoithe sheet redge t6 p'rovid'eianexpo'sedllterminal :areai' of the J-l-1ea`tsea-ling material 5and. a'f'second Isheetmemb'er'l overlying; and .i coextensive withi the paran Wax layer {fithe fifjoint-fcomprising' saidcomposite sheet joinedto'its'eltwith al portionthereof :ex- -Y tending -1 over fand; covering the .f exposedy terminal areafl andwithltthe-' adj a'centv terminal edges sub- I' stantiallyf in abutment with 'the heat sealing surfaces on the rst sheet in face-to-faceengageunent, -the '-petroleumwax?.layer'.` having; .been

meltedv tofprovide' a l seal :between the. adjacent l abutting `terminal edges'iof' the sheet.

'#31 A jointstr-ueturefashionedf from acom- :'70 posite sheetfhaving aliirst sheet` member-having a layer-'o heat' sealingniaterialj on V-each-side thereof, a petroleum Wax layer on one'ofsaid heat sealing' layersterminating-short offrthey sheet edge to provide ariexposedterminal-areaioff-the HSJ Lheati'sea-l-ir'igmaterialjlahd a-secend sheet r,mem-

6 REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,051,903 Royal Aug. 25, 1936 2,106,875 Rowe Feb. 1, 1938 2,374,128 Pinckert 1 Apr. 17, 1945 2,442,936 Rohdin June 8, 1948 

3. A JOINT STRUCTURE FASHIONED FROM A COMPOSITE SHEET HAVING A FIRST SHEET MEMBER HAVING A LAYER OF HEAT SEALING MATERIAL ON EACH SIDE THEREOF, A PETROLEUM WAX LAYER ON ONE OF SAID HEAT SEALING LAYERS TERMINATING SHORT OF THE SHEET EDGE TO PROVIDE AN EXPOSED TERMINAL AREA OF THE HEAT SEALING MATERIAL, AND A SECOND SHEET MEMBER OVERLYING AND COEXTENSIVE WITH THE PARAFFIN WAX LAYER; THE JOINT COMPRISING SAID COMPOSITE SHEET JOINED TO ITSELF WITH A PORTION THEREOF EXTENDING OVER AND COVERING THE EXPOSED TERMINAL AREA OF THE SHEET AND A PORTION OF THE SECOND SHEET MEMBER AND WITH HEAT SEALING SURFACES ON THE FIRST SHEET IN FACE-TO-FACE ENGAGEMENT, THE PETROLEUM WAX LAYER HAVING BEEN MELTED TO PROVIDE A SEAL BETWEEN AND THE SECOND SHEET MEMBER AND OF THE SHEET AND THE SECOND SHEET MEMBER AND THE PORTION OF THE COMPOSITE SHEET OVERLAPPING THE SECOND SHEET MEMBER. 